There's an interesting article in the Washington Post :
"Migranes, Memory Loss: Was it All in His Head?" by Sandra Boodman about a teenager who developed postural orthostatic tachycardia syndrome (pots). People with chronic fatigue or FM often have similar problems with blood pressure or heart rate changing drastically between sitting, standing, or lying down. It is an interesting look at how doctors react to an illness they don't understand. It's the "If we can't understand it, it must be a mental illness" syndrome. (If my link does not work see the
health section of the Post).